(a) Field of the Invention
The present invention relates to a fabrication method for an improved structure of a rubber keypad. More specifically, the present invention relates to the fabrication process for a rubber keypad with a printed character layer formed by a high-temperature, high pressure punching process on a transparent, thin rubber plate.
(b) Description of the Prior Art
A conventional keypad used in a telephone or a cellular phone has a diaphanous design because of the internal light source from the phone. These keypads are traditionally fabricated by punching on a piece of rubber, to form a thin rubber plate with a plurality of protruding blocks. The entire surface is then painted with a dark color. The protruding blocks, i.e., the individual keypads, then undergo a laser process which removes some of the dark paint, leaving markings of numbers and characters on the keypad (such as the `#` and `*` keys, the numbers and the letters). Since laser equipment is required in the above process, the manufacturing cost is high. In addition, repeated finger contacts on the keypad can deteriorate the painted markings on the keypad. Although a keypad for a calculator does not require the painting process, the characters on the keypad still come off after a period of time.